Recently, increasing interest in environmental issues has brought a change of energy source from petroleum and coal to electricity in many industrial fields, and not only the fields of electronics such as mobile phones and laptop computers but also various other fields such as the auto industry and the aircraft industry have begun to use electric accumulators such as cells and capacitors. In keeping with this trend, materials for these electric accumulators have been the subject of intense studies.
Lithium ion cells are most popular among other electric accumulators. They are used as batteries in mobile phones and laptop computers, for example. Unfortunately, the charging and discharging capacity of lithium ion cells is not large enough, and this disadvantage has created a demand for novel cells with a larger charging and discharging capacity. Recently, lithium-air cells, which have a larger theoretical capacity than lithium ion cells, have received attention. There is a study on lithium-air cells which proposes the use of an organic electrolyte (see Non Patent Literature 1).